If Cameron Mackintosh hadn’t decided to produce a London revival of Oliver! in 1978, a far greater theatrical phenomenon — Les Misérables — might never have happened.

Les Miz did happen, of course, and more than 25 years after the English-language version opened in London, a reconceived anniversary edition of the show begins a two-week run Tuesday at the Broward Center for the Performing Arts.

The British producer with the golden touch, now Sir Cameron Mackintosh thanks to the massive worldwide success of Les Miz, The Phantom of the Opera, Miss Saigon and so many other musicals, talked about Les Misérables past and present from his London office last week. Songwriter-turned-librettist Alain Boublil, Mackintosh recalled, traveled from Paris to London in ’78 to see Oliver!. And as Boublil was watching the wily Artful Dodger, he got to thinking about a similar streetwise boy: Gavroche, one of dozens of characters in Victor Hugo’s sprawling 1862 novel.

Boublil went home, got in touch with composer Claude-Michel Schönberg, and the two collaborated on a concept album. The stage version opened and ran for three months at the Palais des Sports in Paris. Mackintosh got involved a couple of years later, putting together a team to adapt the original, working with artists from the Royal Shakespeare Company and overseeing the birth of a show that has played more than 10,000 performances in London since its 1985 opening. Sixty million people have watched the sweeping, through-sung musical full of triumph and tragedy, love and cruelty play out in 21 languages and 42 countries.

And though Mackintosh didn’t write or direct Les Miz, he will acknowledge that he made a difference in the fortunes of what he calls “one of the most extraordinary musicals ever written.”

He adds: “I don’t underestimate the role I’ve had in taking this to another level. Producers don’t create shows. But they can help make a good show great.”

Lawrence Clayton, the first black actor to portray the heroic ex-convict Jean Valjean, believes Mackintosh has added immeasurably to the show.

“Cameron has the uncanny ability to watch three minutes of what you’re doing, then come over and whisper in your ear, ‘Try this.’ He knows the show inside and out. He knows how to turn that last little screw,” Clayton says. “He’s an old-fashioned artistic producer. Most producers today are all about raising money.”

Playing opposite Clayton in the new touring company as Valjean’s dogged nemesis Javert is Cuban-American actor Andrew Varela. Varela, who went to Arvida Middle School in south Miami-Dade, has played numerous roles in Les Miz — including that of Jean Valjean on Broadway. He likens portraying Valjean to running a marathon, Javert to sprinting.

And, encouraged by Mackintosh, he tries to put his spin on the unyielding lawman determined to bring to justice a man whose “crime” was stealing a loaf of bread to feed his starving sister and her children.

“I wanted to bring a humanity to him, to make the audience think. I didn’t want it to be so easy to pigeonhole him as the bad guy,” Varela says. “I’m so grateful to be part of a piece with heft and gravitas. This is definitely in the pantheon of the best shows.”

Generally, when a producer has managed to make a fortune with one of those “best shows,” he doesn’t tinker with a proven artistic commodity. But in revisiting Les Miz for its 25th anniversary, Mackintosh wanted something fresh. He hired a different directing team, Laurence Connor and James Powell, both of whom had acted in the show (Trevor Nunn and John Caird staged the original production). From designer Matt Kinley, Mackintosh got (instead of the original’s famous turntable by John Napier) a set that incorporates projections of paintings by Hugo. Orchestrations evolved. Changing Les Miz, Mackintosh says, just made sense.

“However wonderful the original was, I felt that under normal circumstances several directors would have had a go at new productions of it,”says the producer, who says the show is 10 minutes shorter (without any cuts) and grittier. “It was a hard act to follow, those brilliant tableaux by Trevor and John. . . . But vive la différence!”

One of those differences in the new production is in having a black actor play Valjean. Noting that Clayton was cast “because he was the best,” Mackintosh adds, that “during previews, I realized that the one thing you didn’t want was him not embracing that he was a black man with a black man’s voice.”

So Clayton began to experiment a bit.

“I’m more of a pop, rhythm-and-blues singer than an opera or traditional musical-theater singer,” Clayton says. “I can sing a lot of different styles. But now you may hear a little gospel turn or a blues lick. It’s all done in the spirit of storytelling. . . . The thing I’ve learned is that every way you know how to sing, every trick you know, you’ll use it. You have to pace yourself.”